The long term objective of this research is the development of compact, robust, and user friendly femtosecond-pulse laser sources for applications in biology and medicine. Examples include multi-photon microscopy, optical coherence tomography imaging and femtosecond corneal surgery. Such sources will provide researchers in the biological and biophysical sciences much greater access to new techniques while enhancing and expanding their capabilities. The primary aim is to develop high-energy fiber lasers and semiconductor lasers. As a result of recent advances in these fields, the development of short-pulse sources with capabilities that will exceed those of bulk solid-state lasers is realistic. Fibers and semiconductors offer the possibility of completely integrated devices, which will be required for new short-pulse techniques to attain widespread use. A secondary focus of this work will be the development and application of measurement capabilities in support of multi-photon microscopy. The goal is to clarify the photo physics underlying multi photon techniques. The development of new and/or enhanced capabilities for visualizing and affecting tissue levels at level ranging from molecular to macroscopic has had obvious health benefits and similar or greater impact can be expected in the future.